peter galbraith, one of america's most distinguished diplomats over the years has decided that working with karzai is impossible, and draws some very striking conclusions on america's mission in afghanistan, and on karzai himself. >> one of the explanation, based on what sources inside the palace have said, is that he is -- that he may be using drugs. this behavior is very strange. >> what you have heard within the palace does it speak of particular drugs? >> well, hashish use and marijuana is common in afghanistan. >> after that the editor of "time" magazine, a pulitzer price-winning historian and a new columnist for the "new york times." you won't want to miss any of this. let's get started. >>> peter galbraith has served for many years as an american diplomat and has had a dramatic impact on american policy. in croatia, as ambassador, he sounded the alarm that led to u.s. military involvement in the balkans. as a private citizen, he helped the kurds carve out an autonomous republic within iraq. his most recent posting was to afghanistan, where he was sent by u.n. secretary-general b